Conventional integrated circuit temperature switches or set point controllers which provide a predetermined output signal when a preset temperature is reached suffer from a number of shortcomings. The temperature set point may vary due to a variety of manufacturing variables such as sheet resistance variations, current density errors, and variations in the transistor base to emitter voltages from lot to lot. In some cases the transistors which determine the set point have their collector-base voltages, subject to the supply voltage so that fluctuations in the supply voltage cause changes to the temperature set point due to the Early effect. In addition, attempts to make such devices easily externally programmable have met with indifferent success because of inability to account for various fabrication variables; some require two or more external resistors for set point programming.